Word-based bundler with qualified imports

[toyboot4e]

Allow qualified imports in user-defined libraries and bundle them into a single Main.hs before submission.

Simple word-based replacement doesn't fully resolve name conflicts, but it's better than nothing!

[toyboot4e]

Initial plan:

• Qualified imports have a global scope among all user source files.
• Types, record filed names and functions get file-based scopes with the simple word replace.

[toyboot4e]

Alternative approach is hacking the judge environment.

Here's an example submission code, where {- AC_PROJECT <path> -} denotes a file distribution:

{- AC_PROJECT src/MyLib/F.hs -}
module F (f) where

f :: Int -> Int
f = (+ 1)

{- AC_PROJECT app/Main.hs -}
import MyLib.F qualified as F
main :: IO ()
main = print $ f 1

It would expand to such a project:

.
├── app/
│   └── Main.hs
└── src/
    └── MyLib/
        └── F.hs

Then we can use real qualified imports. Ridiculous, cheating.. but actually solid.